Trepanning
| Trepanning | |
|---|---|
 Detail from The Extraction of the Stone of Madness, a painting by Hieronymus Bosch depicting trepanation (c. 1488–1516) | |
| Other names | Burr hole |
| Specialty | Neurosurgery, neurology |
Trepanning, also known as trepanation, trephination, trephining or making a burr hole (the verb trepan derives from Old French from Medieval Latin trepanum from Greek trúpanon, literally "borer, auger"), is a surgical intervention in which a hole is drilled or scraped into the human skull. This procedure is one of the oldest known surgical procedures, mainly performed by priests or "medicine men." Those who performed trepanation used materials such as stone, obsidian, bronze, or bone shaped into hand-held tools. The intentional perforation of the cranium exposes the dura mater to treat health problems related to intracranial diseases or release pressured blood buildup from an injury. It may also refer to any "burr" hole created through other body surfaces, including nail beds. The process to identify trepanation is through identification of a hole in the skull. The shape of the hole, cutting edges, and the healing process that is from the procedure also helps archeologists identify a trephined skull. A trephine is an instrument used for cutting out a round piece of skull bone to relieve pressure beneath a surface.
Trepanning was sometimes performed on people who were behaving in a manner that was considered abnormal. In some ancient societies it was believed this released the evil spirits that were to blame. Evidence of trepanation has been found in prehistoric human remains from Neolithic times onward. During that time, trephined skulls were commonly found in central Europe. After the Neolithic era, trephined skulls became less common due to the increased use of cremation. The bone that was trepanned was kept by the prehistoric people and may have been worn as a charm to keep evil spirits away. Evidence also suggests that trepanation was primitive emergency surgery after head wounds to remove shattered bits of bone from a fractured skull and clean out the blood that often pools under the skull after a blow to the head. Trepanation was also used for the purposes of removing splinters from head wounds and cranial decompression. Hunting accidents, falls, wild animals, and weapons such as clubs or spears could have caused such injuries. War injuries such as a bullet wound can mimic a trephined skull. Trepanations appear to have been most common in areas where weapons that could produce skull fractures were used. The primary theories for the practice of trepanation in ancient times include spiritual purposes and treatment for epilepsy, head wounds, mental disorders, and headaches, although the latter may be just an unfounded myth. Studies show that trepanation was used on individuals that were diagnosed with epilepsy, scurvy, frontal sinustis, intracranial disorders, diseases, hydrocephaly, and osteitis.
In modern eye surgery, a trephine instrument is used in corneal transplant surgery. The procedure of drilling a hole through a fingernail or toenail is also known as trephination. It is performed by a physician or surgeon to relieve the pain associated with a subungual hematoma (blood under the nail); a small amount of blood is expressed through the hole and the pain associated with the pressure is partially alleviated. Similarly, in abdominal surgery, a trephine incision is when a small disc of abdominal skin is excised to accommodate a stoma. Although the abdominal wall does not contain bone, the use of the word trephine in this context may relate to the round excised area of skin being similar in shape to a burr hole.